Composition and method for coating objects of acrylic resin and coated objects thus obtained

Abstract

A composition for the application of coatings on a substrate having a base of acrylic resin, comprising polymethylmethacrylate dissolved in a solvent composed of at least one ketone selected from methylethylketone and diacetone alcohol and of a chlorinated hydrocarbon selected from trichloroethylene and methylene chloride, the ratio of the volume of chlorinated hydrocarbon to the volume of ketone being at least 20 to 80.

What is claimed is: 
     
       1. A method for obtaining an object having a base of acrylic resin provided with a coating based on polymethylmethacrylate which comprises applying on a substrate having a base of acrylic resin a composition comprising polymethylmethacrylate dissolved in a solvent, wherein said solvent is composed of at least one ketone selected from methylethylketone and diacetone alcohol and of a chlorinated hydrocarbon selected from trichloroethylene and methylene chloride, the ratio of the volume of chlorinated hydrocarbon to the volume of ketone being at least 20 to 80, and evaporating the solvent, and wherein the substrate is flat at the time the coating is applied and the coated object is then subjected to a thermoforming process. 
     
     
       2. A method according to claim 1, wherein the substrate has a base of polymethylmethacrylate. 
     
     
       3. A method according to claim 2, wherein the composition is applied by spray-coating. 
     
     
       4. A method according to claim 3, wherein an unfilled composition and a glass fiber filler are applied simultaneously by spray-coating on the substrate. 
     
     
       5. A method according to claim 2, wherein the composition is applied by hand-coating. 
     
     
       6. A method according to claim 2, wherein the composition is applied by molding. 
     
     
       7. A method according to claim 1 wherein said ratio is at least 60 to 40. 
     
     
       8. A method according to claim 7 wherein said ratio is approximately 70 to 30. 
     
     
       9. A method according to claim 1 wherein said ketone and said chlorinated hydrocarbon are respectively diacetone alcohol and methylene chloride. 
     
     
       10. A method according to claim 1 wherein the ratio of the volume of polymethylmethacrylate volume of solvent is within the range of 5% to 10%. 
     
     
       11. A method according to claim 1 wherein said composition further contains a pigment, or a filler, or both. 
     
     
       12. A method of claim 1 wherein said thermoforming is carried out at a temperature of about 170° C. to about 180° C.